/**************************************************************************//**
* @brief Initializes the capacative touch system with LESENSE.
*
* @param[in] sensitivity
* An array of floats, indication of threshold level, in percent,
* of nominal count value.
*
*****************************************************************************/
void LETOUCH_Init(float sensitivity[]){
uint8_t i;
channels_used_mask = 0;
num_channels_used = 0;
/* Initialize channels used mask and threshold array for each channel */
/* Uses the sensitivity array to deduce which channels to enable and how */
/* many channels that are enabled */
for(i = 0; i < NUM_LESENSE_CHANNELS; i++){
/* Init min and max values for each channel */
channel_max_value[i] = 0;
channel_min_value[i] = 0xffff;
/* Add to channels used mask if sensitivity is not zero */
if(sensitivity[i] != 0.0){
channel_threshold_percent[i] = sensitivity[i];
channels_used_mask |= (1 << i);
num_channels_used++;
}
}
/* Disable interrupts while initializing */
INT_Disable();
/* Setup CMU. */
LETOUCH_setupCMU();
/* Setup GPIO. */
LETOUCH_setupGPIO();
/* Setup ACMP. */
LETOUCH_setupACMP();
/* Setup LESENSE. */
LETOUCH_setupLESENSE();
/* Do initial calibration "N_calibration_values * 10" times to make sure */
/* it settles on values after potential startup transients */
for(i = 0; i < NUMBER_OF_CALIBRATION_VALUES * 10; i++){
LESENSE_ScanStart();
LETOUCH_Calibration();
}
/* Setup RTC for calibration interrupt */
LETOUCH_setupRTC();
/* Initialization done, enable interrupts globally. */
INT_Enable();
}
/***************************************************************************//**
* @brief
* Set scan mode of the LESENSE channels.
*
* @details
* This function configures how the scan start is being triggered. It can be
* used for re-configuring the scan mode while running the application but it
* is also used by LESENSE_Init() for initialization.
*
* @note
* Users can configure the scan mode by LESENSE_Init() function, but only with
* a significant overhead. This simple function serves the purpose of
* controlling this parameter after the channel has been configured.
* Please be aware the effects of the non-atomic Read-Modify-Write cycle!
*
* @param[in] scanMode
* Select where to map LESENSE alternate excitation channels.
* @li lesenseScanStartPeriodic - New scan is started each time the period
* counter overflows.
* @li lesenseScanStartOneShot - Single scan is performed when
* LESENSE_ScanStart() is called.
* @li lesenseScanStartPRS - New scan is triggered by pulse on PRS channel.
*
* @param[in] start
* If true, LESENSE_ScanStart() is immediately issued after configuration.
******************************************************************************/
void LESENSE_ScanModeSet(LESENSE_ScanMode_TypeDef const scanMode,
bool const start)
{
uint32_t tmp; /* temporary storage of the CTRL register value */
/* Save the CTRL register value to tmp.
* Please be aware the effects of the non-atomic Read-Modify-Write cycle! */
tmp = LESENSE->CTRL & ~(_LESENSE_CTRL_SCANMODE_MASK);
/* Setting the requested scanMode to the CTRL register. Casting signed int
* (enum) to unsigned long (uint32_t). */
tmp |= (uint32_t)scanMode;
/* Write the new value to the CTRL register. */
LESENSE->CTRL = tmp;
/* Start sensor scanning if requested. */
if (start)
{
LESENSE_ScanStart();
}
}
